Heavy equipment and machinery frequently require repair and it is generally preferable that such repair be done in the field rather than transporting the machinery or the equipment to a suitable repair facility as field repair reduces the associated time and cost required for repair. One of the most commonly required repairs for large machinery or equipment is the repair of a bore, that is, a circular opening that supports an axle or a shaft, for example. These circular openings become damaged or excessively worn due to a variety of reasons and causes, including mechanical wear of the parts, resulting in a need to restructure or reconstruct the bore to it original shape and diameter or possibly add a layer to a surface of the bore (e.g., “cladding”). It may also be desirable to modify a bore for any of a number of reasons, such as reconstructing the bore with a greater or a small diameter to accommodate a different sized shaft or axle, etc.
The repair of a damaged or worn bore or the modification of a bore for any reason typically involves rebuilding the interior surface of the bore by the deposition of a metal, typically by a welding or a flame deposition process, and then the subsequent boring and/or machining of the rebuilt or refabricated bore to the precisely required internal diameter. The material addition process is typically performed in the field by a rotatable portable welding or flame deposition device while the machining process is typically performed in the field by a portable boring machine which has a boring bar that is inserted into the bore. The boring bar is typically supported by a pair of spaced apart bearings located on each side of the bore being repaired and typically supports one or more replaceable tools for machining the bore, such as a variety of conventual cutting or machining tools for machining and/or finishing the surface of the bore being repaired.
As is conventional in the art, the boring bar is supported at each opposed end thereof by bearings which provide the radial support and rigidity for the tools that are necessary for accurate machining and/or finishing of a bore. It is to be appreciated that accurate reconstruction of a bore requires the accurate guidance of welding device as well as the boring bar supporting the machining and/or finishing tool(s) through the bore to achieve the desired bore diameter and alignment as well as the desired machined finish on the interior surface of the bore.
The application of a continuous layer (or layers) of a weld bead on the inside surface of a bore that forms a welded “shell” of a generally smaller inside diameter than the previous bore size, without rotating the part that contains the bore, is commonly referred to as “bore welding”. The bore welding process has been refined in various respects over the years, but has generally maintained the same basic size, design and configuration. Issues that continue to be of concern with the existing bore welding machines typically center around the size and the weight of the bore welding equipment. It is not an infrequent occurrence that some bore welding situations cannot easily be handled with existing bore welding equipment because of the size of the currently available equipment does not easily permit use within the available space so that such bore to be repaired can be readily rebuilt. Bore alignment issues can also arise because the weight of the equipment may possibly cause deflection of a support component (or components) that is essential for proper alignment of the bore welding equipment with the bore to be repaired. Other issues involve reliability of electrical and mechanical components of the bore welding equipment, which are often complex and somewhat cumbersome to use, particularly in confined spaces.
The present invention is directed at improvements concerning bore welding equipment and, in order to more clearly illustrate the nature of such improvements and in order to provide a context for such improvements, the following will first describe exemplary bore welding equipment in which such improvements may be implemented. As the present invention generally relates to modifications concerning U.S. Pat. Nos. 6,137,076, 6,284,995, 6,448,531 and 6,737,738, a brief discussion concerning such prior art portable welding device will first be provided and the disclosure of such patents are incorporated herein by reference.